package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author 寒士obj
 * @date 2025/07/05 16:21
 **/
@Component
public class RedisIdWorker {

    private static final long BEGIN_TIMESTAMP = 1640995200L;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public long nextId(String keyPrefix) {
        // 1. 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        // 2. 生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        // 3. 拼接并返回：符号位（1位） 时间戳（31位） | 序列号（32位）
        return timestamp << 32 | count;
    }
}
